One of the many words that Australians have
cut syllables off and replaced with "-o". This
one represents the hours after 12pm, and is used by people, myself included, who can'
t be bothered saying "-fternoon".
Hey
Davo, I'm goin' to the servo for arvo smoko.
Translation:
David, I'm going to the service station to purchase some food for the afternoon
break.